Adjustable test tube racks



Aug. 10, 1965 R. L. BRADLEY ADJUSTABLE TEST TUBE RACKS Filed July 6,1964 INVENTOR B R A D L E Y REX ATTORNEY United States Patent 3,l9,684ADJUSTABLE TEST TUBE RACKS Rex Lee Bradley, 367 E, 45 /2 St., Austin,Tex. Filed .laly 6, $64, Scr. No. 380,430 6 Ciaims. (Cl. 211-74) Thisinvention relates to laboratory and medical equiprnent and moreparticularly concerns test tube racks especially designed to holdlaboratory test tubes at an inclined angle.

Display racks of various sorts have long been used to hold specimen andmaterial samples at a fixed inclined angle for more efiective viewing ofthe contents. Laboratory supply houses also offer a commercial line ofracks designed to provide for safe and efficient storage of test tubesand some of these also provide means for supporting part or all of thetubes at an angle that permits washed tubes to drain. In each of theseracks the angle of inclination is fixed and holds the tube in almostvertical position. There are instances, however, there are othersituations, however, in the work performed in medical and chemicallaboratories where the test tube needs to be held securely at anadjustably inclined angle during the preparation of gelatinous mediasand during the performance of some tests Where cultures are grown inclosed test tubes, said tubes need to be supported at almost ahorizontal angle of inclination. In instances where the primary growthof microbes, bacteria, molds or other culture growth occurs primarily onthat part of a soft or fluid media where the media surface is exposed toair, supporting the test tube at a near horizontal angle will produce alarger elliptical surface area for the growth of microbes and the like,but the angle of inclination must be adjusted in such a manner as topreserve a media but in the bottom of the test tube to permitobservation of gas produced by the microbes.

In addition to needing a test tube rack that can be adjusted to hold thetubes at an optimum angle of inclination there are instances in whichthe accuracy of successive comparative tests over a period of time isdependent upon being able to accurately duplicate the exact same angleof inclination used in the previous tests. Accordingly, it is the objectof this invention to produce a rack for test tubes that can be adjustedby the operator to hold the tubes at a selected or optimun angle ofinclination and that can be accurately reset to the same angle ofinclination used in previous tests.

Another object of the invention is to produce an adjustable test tuberack that will hold a large number of test tubes in a compact space andhold all of the tubes at the same angle of inclination.

Still another object is to create an adjustable test tube rack with amultiplicity of staggered trays so arranged that the contents ofparticular test tubes can be observed on any tray without having todisturb test tubes in that or other trays.

It is a further object of the invention to provide the trays of saidrack with such guide means for the test tubes as will prevent the tubesfrom rolling laterally and touching or bumping each other or havingtheir angle of inclination disturbed by rolling into a differentposition in the slanting tray. This is particularly important when therack and all of its contents must be carried from one work area toanother with minimum disturbance to the cultures in the test tubes.

And it is the purpose of this invention to incorporate these featuresinto a test tube rack of such simplicity as to combine ease and economyof manufacture with features that make the rack and its test tube guideseasy to clean and sterilize to laboratory standards of sanitation.

Other objects and advantages of this invention will be tangent apparentfrom the following description, when read in connection with theaccompanying drawings, wherein:

FIGURE 1 is a perspective of a test tube rack showing a preferredembodiment of this invention.

FIGURE 2 is a side cross section view along lines 22 at the mid sectionof the preferred embodiment of the invention shown in FIGURE 1.

FIGURE 3 is a partial section of the upper tray along lines 3-3 ofFIGURE 1.

In describing the preferred embodiment of the invention shown in thedrawings, specific terminology will be used for the sake of clarity.However, it is not intended to limit the invention claimed to thespecific terms set forth, and it should be understood that each of thespecific items used for illustration is to be considered as includingall technical equivalents which operate in a similar mannor toaccomplish a similar purpose. Referring to the preferred embodiment ofthe invention selected'for illustration in the drawings the number 11designates generally a mounting frame which provides support for aplurality of staggered trays 16. Said trays are attached to frame 11 bypivots 19 in a manner that permits the trays to be adjusted to hold testtubes placed in such trays in an inclined position. The front ends oftrays 15 are supported by pivotal connections 29 to right and left sidebars 21 and 22 in such a manner that all of the trays remain in aparallel position as they rotate with respect to mounting frame 11 sothat the test tubes in all tray are supported at the same angle ofinclination. Protractor segment 23 and index mark 24 together withwingnut clamp screw assembly 25 enable the operator to adjust and lockthe test tube trays at the angle desired. In addition, the protractorsegment enables the operator to accurately duplicate the angle of slantin running subsequent tests or experiments. The test tubes are preventedfrom bumping each other or rolling laterally within the trays by use ofcorrugated test tube guides 26, 27 and 28 which are designed for quickand easy insertion and removal from trays 16 to facilitate the cleaningand sterilization of the equipment.

Returning to FIGURE 1, it will be seen that mounting frame 11 comprisesan upright back 12 and right and left side plates 13 and 14 with theirfront edges sloping at a convenient angle. A strip approximately afraction of an inch which may be turned under along the lower edge ofside plates 13 and 14 and perhaps along the bottom of back 12 to providefeet 15 for the mounting rack but in the interest of sanitation andconvenient cleaning use of a bottom plate should be avoided.

A plurality of flat-bottomed trays 16 are formed, each with turned upsides 17 and a turned up back 18 and with an open top and front. Aplurality of pivots 19 pivotally secure trays 16 through the rear ofsides 17 to points along the front sloping edge of side plates 13 and14'.

Trays 16 are secured and supported at the front by means of pivots 26 toright and left side bars 21 and Z2. Pivots 26 are spaced to pass throughside bars 21 and 22 at points that correspond with the positioning ofpivots 19 along the front edges of side plates 13 and 14 so that trays16 remain parallel to each other as they rotate with respect to mountingframe 11. A protractor segment 23 is attached to one or both side bars21 or 22 with its center point concentric with one of the pivots 2i andappropriate index mark or marks 24 on the side or sides of tray 16 suchthat reading protractor segment 23 against index mark 24 indicates theangle of inclination for all of the trays. It should be readily apparentthat index marks and protractor segments or an equivalent angleindicating device could be mounted at any number of points along sideplates 13 and 14 or along side bars 21 and 22 to indicate the angle ofinclination of trays l6 and that the incorporation of any equivalentdevice for determining the 3 angle of inclination of the trays 16 fallwithin the scope of the invention described and claimed herein.

In order to provide means for adjustment of the tray angle ofinclination as required for a particular usage, a position lockingdevice 25 is incorporated into one or more of pivot points 19 or 2%. Inthe embodiment illustrated in the drawings, herein, the position lockingdevice employed is a screw and wingnut. It will be readily apparent thatany of a number of friction locking devices could be employed and thatthe inclusion of lockwashers or friction surfaces as appropriate pointsmay be used to increase the effective security of the friction lockingdevice.

An alternate means of providing even more secure adjustment of the angleof inclination of the trays would be to use a diagonal clamp bar (notshown) pivotally connected at one of its ends to'an appropriate point atthe front of one of the trays or along side bars 29 or 21 and adjustablysecured at an appropriate point on side plates 13 or 14- to produce atriangular brace. If continuous adjustment of the tray angleof-inclination is required such adjustment may be accomplished byproviding a slot in either side plates 13 or 14 or in the diagonal clampbar and adjustably securing the diagonal clamp bar to the side plate bymeans of a friction locking device. Where step adjustment of the angleof tray inclination is practical, one of the securing surfaces may beprovided with a series of spaced apart notches and the other securingsurface provided with a catch device designed to engage with theselected notch. Such equivalent variations in the means of accuratelyadjusting or readjusting the angle of tray inclination are claimed to bewithin the spirit of the invention described and claimed herein.

During operation, the test tubes need to be maintained at right anglesto the axis of inclination and such test tube guide means is provided byuse of corrugated insert plates 26, 27 or 28. Such corrugated test tubeguide means may be made of metal, plastic or appropriate smooth surfacedmaterial that will withstand repeated scrubbing and sterilization orthat is sufficiently inexpensive that the corrugated guide means can bereplaced with a new guide after being used a few times. The corrugatedguide means could be incorporated into the upper surface of trays 16 butsuch would so seriously interfere with cleaning and sterilization oftrays 16 that it appears more prudent to preserve the fiat, smooth andeasily cleaned surfaces of trays 15 and make the corrugated guide meansin the form of an insert plate that is removable and replaceable.

Three different kinds of corrugated test tube guide means are shown inplace on trays 16 in the drawings. Test tube guide means 26 isfabricated from corrugated sheet material and is provided with clips 29to hold it securely in place in tray 15. Test tube guide means 27 couldbe cast or moulded to produce a flatbottom and a corrugated uppersurface and may be held in place by clips 29, by retainer flanges alonginside surface of tray sides 17 or fabricated to fit into place sosnugly as to be held in position by friction. Guide means 28 is similarexcept that it has V-shaped instead of rounded corrugations on its uppersurface. It should be apparent again that trays 16 could be providedwith parallel flanges, grooves, ridges, punched up tabs or other meansof providing test tube guides without departing from the scope of thisinvention.

FIGURE 3 is a partial cross section along lines 3-3 in FIGURE I anddesigned to illustrate that the use of relatively small and closelyspaced corrugations for guide means 26 will make it possible toaccommodate test tubes 30 of a range of diameters with a single size ofcorrugation and still prevent the test tubes from rolling laterally ortouching or bumping each other.

The advantages of preserving smooth and easily cleaned surfaces in thepermanent and more expensive parts of the rack proper while providing aninexpensive disposable and replaceable insert tray as a guide means forthe test tubes will appeal to those familiar with scrubbing laboratoryequipment. Staggered arrangement of the trays permits the operator toread the labels on each tube without touching any of the test tubes andindividual tubes may be withdrawn for at least two thirds of theirlength for inspection of contents as shown in the dashed lineillustration in FIGURE 2 without bumping or displacing adjacent or othertubes in the tray. Creation of a test tube rack with an adjustable angleof inclination meets a long felt need while the addition of a protractorsegment or angle measuring and indicating device provides an element ofaccuracy and convenience beyond the expectations of even the mostexperienced laboratory personnel and enables the operator to reproducethe exact same angular adjustment of the trays for subsequentexperiments.

The particular configuration of the rack with the arrangement ofstaggered trays provides a means of angular support for a large numberof test tubes without obscuring visibility of the tubes or theircontents and holds all of the tubes in the rack at the same angle ofinclination.

It is to be understood that although the foregoing specification hasdescribed only a limited number of preferred embodiments of structurethat it is possible to produce still other embodiments without departingfrom the inventive concept disclosed herein, and it is therefore desiredthat only such limitations be imposed on the appended claims as arestated therein, or are required by the prior art.

Having thus described my invention, I claim:

1. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame, a plurality of trays adaptedto receive and hold test tubes, said trays pivotally connected to thesupporting frame in staggered positions, side bars pivotally connectedto the front corners of each tray to provide adjustable support at thefront of the trays, a position locking device, a position indicatingdevice and test tube guide means.

2. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame; a plurality of trays adaptedto receive and hold test tubes; pivots at the rear corners of each trayto connect the trays to the supporting frame in staggered positions andprovide angular adjustment of the trays with respect to the supportingframe; left and right side bars to provide adjustable support for thefront of said trays; the front ends of each tray being pivotallyconnected to said side bars in such manner as to hold all of the traysin parallel positions; a position locking device through at least one ofthe pivot points to secure the trays in the desired angular position, anangle indicating device composed of a protractor segment and an indexmark adapted to indicate the angular position of the trays; and testtube guide means in which corrugated guides are fabricated into thesurface of an insert plate that is removable, sterilizable andreplaceable.

3. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame; a plurality of trays; therear corners of said trays being pivotally connected to the supportingframe in such manner as to produce a staggered arrangement of trays andprovide for adjustment of the angle of inclination of said trays; leftand right side bars pivotally connected to the front corners of thetrays in such manner as to maintain all of the trays in parallelrelation to each other and to provide adjustable support for the frontof said trays; a friction locking device through at least one of thepivot points to secure the trays in the desired angular position; anangle indicating device adapted to indicate the angular position of thetrays; and test tube guide means in which corrugated guides arefabricated into the surface of an insert plate that is removable,sterilizable and replaceable.

4. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame; a plurality of trays; therear corners of said trays being pivotally connected to the supportingframe in such manner as to produce a staggered arrangement of trays andprovide for adjustment of the angle of inclination of said trays; leftand right side bars pivotally connected to the front corners of thetrays in such manner as to maintain all of the trays in parallelrelation to each other and to provide adjustable support for the frontof said trays; a position locking device through at least one of thepivot points to secure the trays in the desired angular position inWhich the locking device is a screw and Wingnut assembly; an angleindicating device composed of a protractor segment and an index markadapted to indicate the angular position of the trays and test tubeguide means in which corrugated guides are fabricated into the surfaceof an insert plate that is removable, sterilizable and replaceable.

5. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame; a plurality of trays; therear corners of said trays being pivotally connected to the supportingframe in such manner as to produce a staggered arrangement of trays andprovide for adjustment of the angle of inclination of said trays; leftand right side bars pivotally connected to the front corners of thetrays in such manner as to maintain all of the trays in parallelrelation to each other and to provide adjustable support for the frontof said trays; a position locking device comprising a diagonal clamp barwith one end pivotally connected to the front of at least one of thetrays and the other end adjustably secured to an appropriate point on atleast one of the side plates to produce a triangular brace that locksthe trays into the desired angular position; an angle indicating deviceadapted to indicate the angular position of the trays and test tubeguide means in which corrugated guides are fabricated into the surfaceof an insert plate that is removable, sterilizable and replaceable.

6. A test tube rack adapted to hold test tubes at an adjustable angle ofinclination comprising a supporting frame; a plurality of trays; therear corners of said trays being pivotally connected to the supportingframe in such manner as to produce a staggered arrangement of the traysand provide for adjustment of the angle of inclination of said trays;left and right side bars pivotally connected to the front corners of thetrays in such manner as to maintain all of the trays in parallelrelation to each other and to provide adjustable support for the frontof said trays; a position locking device through at least one of thepivot points to secure the trays in the desired angular position, anangle indicating device composed of a protractor segment and an indexmark adapted to indicate the angular position of the trays; With testtube guide means fabricated into the surface of the trays.

References Cited by the Examiner UNITED STATES PATENTS 884,428 4/08Strong 312201 1,664,130 3/28 Rae 211130 1,821,621 9/31 Durand 2111262,228,775 1/41 Morgan 211128 2,234,032 3/41 West 21l-l28 2,483,263 9/49Cummings 211130 2,532,604 12/50 Carski 21174 2,584,489 2/52 Morrison211142 2,961,101 11/60 Hutton 21l133 CLAUDE A. LE ROY, Primary Examiner.

1. A TEAST TUBE RACK ADAPTED TO HOLD TEST TUBES AT AN ADJUSTABLE ANGLE OF INCLINATION COMPRISING A SUPPORTING FRAME, A PLURALITY OF TRAYS ADAPTED TO RECEIVE AND HOLD TEST TUBES, SAID TRAYS PIVOTALLY CONNECTED TO THE SUPPORTING FRAME IS STAGGERED POSITIONS, SIDE BARS PIVOTALLY CONNECTED TO THE FRONT CORNERS OF EACH TRAY TO PROVIDE ADJUSTABLE SUPPORT AT THE FRONT OF THE TRAYS, A POSITION LOCKING DEVICE, A POSITION INDICATING DEVICE AND TEST TUBE GUIDE MEANS. 